fix(engine): re-poll safe-area insets after app resume

refresh_insets gated its loop on insets.is_populated(), so once insets
resolved at first launch, rearm_on_resumed's poll-counter reset was a
no-op and JNI was never queried again. Insets that changed while the
app was backgrounded (fold/unfold, rotation, gesture/3-button nav
switch) stayed stale until process restart.

Gate the loop on the poll counter alone and settle a cycle by
exhausting it once a populated reading arrives. The cached resource is
rewritten only when the value actually differs, so resumes where
nothing moved trigger no change detection and no relayout — preserving
the no-flash resume behaviour. Also correct the stale on_app_resumed
doc that still described the old inset-zeroing approach.

Closes #116

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

solitaire_engine/src/safe_area.rs

@@ -191,10 +191,12 @@ fn apply_safe_area_to_modal_scrims(
 /// whatever `SafeAreaInsets` are current at that moment.
 ///
 /// On Android the `android::rearm_on_resumed` system runs in the same frame
-/// and resets both `SafeAreaPollTries` and `SafeAreaInsets` to zero, causing
+/// and resets `SafeAreaPollTries` (the cached `SafeAreaInsets` keep their
-/// `refresh_insets` to re-poll JNI over the next few frames.  When it resolves
+/// last-known values), causing `refresh_insets` to re-poll JNI over the next
-/// the correct values, `on_safe_area_changed` in `table_plugin` emits a second
+/// few frames.  If the insets changed while backgrounded, `on_safe_area_changed`
-/// synthetic `WindowResized` and the layout converges to the right position.
+/// in `table_plugin` emits a second synthetic `WindowResized` and the layout
+/// converges to the right position; if they didn't, nothing is rewritten and
+/// the layout stays put.
 ///
 /// On non-Android targets this handler still fires — it ensures that a resume
 /// event always refreshes the layout (e.g., after a minimise/restore on
@@ -232,9 +234,14 @@ mod android {
     pub(super) struct SafeAreaPollTries(pub u32);
 
     /// Polls Android for safe-area insets until we get a non-zero
-    /// reading, then stops. `getRootWindowInsets()` returns `null` (or
+    /// reading, then settles until [`rearm_on_resumed`] re-arms it on the
-    /// all-zero `Insets`) until the decor view has been laid out, which
+    /// next foreground resume — insets can change while backgrounded
-    /// is typically frame 1–3 of a fresh launch.
+    /// (rotation, fold/unfold, gesture ↔ 3-button nav). The poll counter
+    /// (not `insets.is_populated()`) gates the loop, so a re-armed cycle
+    /// re-queries JNI even though cached values are already populated.
+    /// `getRootWindowInsets()` returns `null` (or all-zero `Insets`)
+    /// until the decor view has been laid out, which is typically frame
+    /// 1–3 of a fresh launch.
     pub(super) fn refresh_insets(
         mut insets: ResMut<SafeAreaInsets>,
         mut poll: ResMut<SafeAreaPollTries>,
@@ -243,19 +250,26 @@ mod android {
         // devices that genuinely report zero insets.
         const MAX_TRIES: u32 = 120; // ~2 seconds @ 60 fps
 
-        if poll.0 >= MAX_TRIES || insets.is_populated() {
+        if poll.0 >= MAX_TRIES {
             return;
         }
         poll.0 += 1;
 
         match query_insets() {
             Ok(v) if v.is_populated() => {
+                if *insets != v {
                     info!(
                         "safe_area: insets resolved top={} bottom={} left={} right={} (after {} frames)",
                         v.top, v.bottom, v.left, v.right, poll.0
                     );
                     *insets = v;
                 }
+                // Settled for this poll cycle; `rearm_on_resumed` re-arms on
+                // the next resume. Writing `insets` only on an actual change
+                // keeps resource change detection (and the relayout it
+                // triggers) quiet on resumes where nothing moved.
+                poll.0 = MAX_TRIES;
+            }
             Ok(_) => {
                 // Layout not ready yet; try again next frame.
             }